The inexhaustible and renewable sources of energy which are being produced continuously in nature are called non conventional sources of energy.They are abundant in nature.They do not produce environmental pollution and they donot require heavy expenditures to produce energy.If they are utilized well,they can help in overcoming energy crisis because of their cheap availability.

The main non-conventional sources of energy are:

1. Wind Energy2. Solar Energy 3. Tidal Energy

Wind energy:

Two factors are responsible for causing winds.Firstly,wind is caused by absorption of solar energy on the surface of earth and in the atmosphere.Secondly,the rotation of earth about its axis and its motion around the sun causes winds.
Wind power helps in pumping water,grinding grain and producing electricity.A wind mill harnesses wind power and converts kinetic energy of moving air into mechanical energy that can be further used in producing electricity or running a machine.
A consistent windflow is necessary for an effective wind system.The basic wind energy conversion device is the wind turbine.

The production of energy by wind has both advantages and disadvantages.

Advantages:

Its advantages are,

After once setting up the system,it makes sure low cost production of electricity.

It is non-polluting,safe and clean.

It doesn't need transportation.

Wind power can be used with hydroelectric plants.With its help water level in the reservoir can be maintained for longer periods.

Disadvantages:

Its disadvantages are,

It creates noise pollution.

Wind mills are expensive to set up.

It disturbs radio and T.V perception.

Wind power is not consistent and steady which is responsible for complications in designing the whole plant.

It has low power coefficient.

Solar Energy:

The energy which comes from sun is called solar energy.The sun is the most abundant,inexhaustible and universal source of energy.In fact all other sources of energy are dependent on sun.The sun produces energy by nuclear fusion reaction that takes place deep in it.When hydrogen nucleus fuses into helium nucleus,the output energy of these reactions flows out from the sun and escapes into the space.All life on earth is dependent upon solar energy.
Solar energy is often called as radiant energy as there are many kinds of radiant energy emitted by sun.For example,e light infrared rays,Ultra violet rays and X- Rays.
Solar energy can be converted into electrical energy by means of photo voltaic effect.Photo means "light" and voltaic means "electric" so it is the conversion of light or other electromagnetic radiation in to electricity.

Advantages:

Solar energy is inexhaustible.

It is non-polluting.

Disadvantages:

It is expensive.

As it is diffused source so it gets wasted.

Tidal Energy:

Tide is periodic rise and fall of the water level of the sea under the influence of gravitational pull of moon and sun.Tides can be used to produce electrical power which is also known as tidal power.Dams or Barrages are constructed in such a way that the basin is filled during high tide and emptied during low tide.The Potential energy of the water stored in the basin is used to drive the turbine which then generates electricity .

There are three main Components of a tidal Power plant. i.e,

(i) The Power house (ii) The dam or barrage (iii) Sluice-ways from the basins to the sea and vice versa.

Advantages:

It is free from pollution.

It is better than hydro power plant because it is not dependent on rain and the tide cycle is definite so there is surety of power supply.

When it is combined with thermal or hydroelectric system,it gets the capacity to meet high power demand.

Disadvantages:

These power plants are dependent on availability of natural sites.

The capital cost of plant is high in comparison with conventional power plants.

As the moon influences the tidal rythm so the output of tidal power varies with lunar cycle.

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The Following User Says Thank You to Farrah Zafar For This Useful Post:

wind is caused by absorption of solar energy on the surface of earth and in the atmosphere Secondly,the rotation of earth about its axis and its motion around the sun causes winds

the bold word seems doubtul can you plz mention the reference

1- The warmer the air, the lower the air pressure. The cooler the air, the higher the air pressure. The higher the difference in pressure, the higher the pressure gradient. The higher the pressure gradient, the stronger the Winds.

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